How to get the difference between two lists?

[jbv]

>
> I like this one, Ken.  In general, I'd reconsider the overall design.
> Specifically, I'd think about queries that do what you want.  If the
> set has to be a single value, then I'd consider a blob that represents
> a bit set as the db representation.
>

well, I don't know...
I've been heavily using Rev cgi and mySQL during the past
few months, and I found out that extracting raw data from the
db and processing them (sorting, comparing...) in Transcript
is most of the time much faster than writing sophisticated
SQL code...
JB